A Professor passed one sixth of his life in childhood, one twelfth in youth, and one seventh more as a bachelor, five years after his marriage a son was born who died four years before his father at half his final age, then what is the age of Professor? $84$ years $74$ years $64$ years $54$ years

A software engineer has the capability of thinking $200$ lines of code in five minutes and can type $200$ lines of code in $10$ minutes. He takes a break for five minutes after every $10$ minutes. How many lines of code will he complete typing after an hour? $200$ $300$ $400$ $500$

Suppose a fraud shopkeeper sells rice to the customer at the cost price, but he uses a false weight of $900$ gm for a kg then his percentage gain is ______ $5.75 \%$ $5.56 \%$ $5.20 \%$ $5.00 \%$

A construction company ready to finish a construction work in $180$ days, hired $80$ workers each working $8$ hours daily. After $90$ days, only $2/7$ of the work was completed. How many workers are to be increased to complete the work on time? Note: If additionally acquired workers do agree to work for $10$ hours daily. $90$ workers $80$ workers $65$ workers $85$ workers